Before means of transport for conveying passengers, such as aircraft, buses, trains or ships, take off or depart after a stop, a boarding procedure of the passengers to be conveyed by the means of transport takes place. With respect to aircraft, this boarding procedure is normally simply referred to as boarding. In passenger air traffic, boarding is understood to mean the phase between calling the passengers to proceed to the gate from which the aircraft standing ready for the booked flight can be reached, and the time when the aircraft doors are locked. After completion of the boarding procedure, the on-board responsibility passes from the ramp agent (an airline or airport employee working on the ground, who prepares aircraft for departure) to the captain.
In the case of larger means of transport, such as larger aircraft, often passengers whose seats are in the rear cabin section are allowed on board first. In the case of very large aircraft, sometimes passengers are called according to seat rows (from the rear to the front), in order to speed up the boarding. After the rear seats, the passengers for the middle seats and finally the passengers for the front seat rows are requested to board.
In the case of means of transport with a plurality of boarding paths for boarding the means of transport (such as for example a plurality of entrances or a plurality of paths to the plurality of entrances), the passengers usually board in an uncoordinated manner, which may lead to crossings of the passengers' paths, inter alia, in the means of transport itself.